Traffic signal controller



5 Sheets-Sheet 1 Filed Jan. '7, 1964 HIS ATTORNEY 5 Sheets-Sheet 2 INVENTOR.

N. A. BOLTON TRAFFIC SIGNAL CONTROLLER NA. BOLTON May 10, 1966 Filed Jan. '7, 1964 HIS ATTORNEY May 10, 1966 N. A. BOLTON TRAFFIC SIGNAL CONTROLLER 3 Sheets-Sheet 5 Filed Jan. 7, 1964 m www@ zoomdw F m Y opzoo XE2: N m ,229m 9. mm R n m0 .M o n H w @L E it -w om m@ Nw- NMNIUI U A @am \moz 0 /mnm @.61

tions.

3,251,031 TRAFFIC SIGNAL CONTRQLLER Norman A. Bolton, Scottsville, N.Y., assiguor to General Signal Corporation, Rochester, N.Y., a corporation of New York Filed Jan. 7, 1964, Ser. No. 336,259

16 Claims. (Cl. 340-41) This invention relates to a highway traflic signal controller and more particularly pertains to such a controller of the pre-timed type in which all active elements for controlling fthe trac signal during the different portions of the traic cycle are optically controlled.

United States Patent O In the cyclic operation of go, stop and tratiic change signals at an intersection, it is usual to employ a cam shaft having a plurality of cams which are so positioned as the cam shaft rotates to engage contacts for completing signal circuit for controlling the traflic signal. In this connection, a timing circuit is employed for measuring the time interval for each of the different portions of a traffic signal cycle for controlling the pulsing of a magnet or relay for driving the cam shaft between its different positions in succession. However, because of the mechanical movement of the cams involved and the physical contact of the cams with respective circuit closing contacts, the cams frequently become worn and dislocated from their normal positions such that one or more cams may fail to properly close their respective circuit closing contacts.

It is proposed in the present invention to provide a traino signal controller employing optical coupling means with active elements to overcome the mechanical limitations of the cam shaft and circuit closing contacts normally employed in traic signal controllers. More particularly, it is proposed to provide an optical countercircuit in the form of a step-by-step counter for demarcating the different portions of the traic cycle in which different combinations of traffic indications are displayed. The optical counter circuit includes a plurality of elements for each of several counting positions thereof which may be operated by light energy coupled from a light generating means for completing signalcontrol circuits as well as a timing circuit for measuring the time interval that the tratiic signal controller remains in each of its counting positions. It is further proposed to provide in this invention pulsing circuit means including normally inactive elements and light generating means responsive to the termination of a measured time interval for advancing the optical counter circuit from one position (to a succeeding position in which the traffic signal is controlled to display a different combination of traic signal indica- In this connection, a hold circuit means is provided for maintaining the light generating means energized for rthe operating position of the ring counter circuit until such time as the time interval for that position is electronically measured.

The light generating meansmay take the form of a neon glow discharge lamp in each instance which has the characteristic of requiring a predetermined potential difference applied across its terminals to cause conduction therebetween. The conduction of such neon tube may be maintained by continually providing such difference in potential between its terminals. Each of the elements responsive to light energy may be a conventional photoconductor element which normally has a high resistance, but upon receiving light energy on a light detecting element thereof, such resistance is reduced to a relatively low resistance. In the various circuits comprising the present invention, suitable optical coupling means are provided between the neon tubes and associated photo- .conductor elements such that the light energy from an lCe energized neon tube only is permitted to be coupled to particular photoconductor elements for completing associatedv circuits.

The employment of neon tubes in association with photoconductor elements for each position of the optical counter circuit with suitable means for optically coupling the light energy of the neon tubes to photoconductor elements in each such position provides in a traffic signal controller an e'icient arrangement which is durable and substantially maintenance free.

Thus, one subject of this invention is to provide a trafc signal controller including a step-by-step counting means in which a normally inactive element responsive to received light energy is employed for each step for electrically coupling control energy to the traffic signal for causing it to display a combination of signal indications allotted to that step of the step-by-step means.

Another object of this invention is toprovide atraflic signal controller in which each portion of the traffic signal is measured by an electronic .timing circuit and demarcated by the control of a light generating means.

Another object of this invention is to provide a'v traftic signal controller in which optical coupling is utilized in operating between the different steps of a step-by-step means each'step of which deiines a portion of the traic cycle.

Another object of this invention is to provide a traic signal controller which utilizes substantially throughout neon tubes and photoconductor elements which provide an eflicient, durable and substantially maintenance free traine signal controller.

Other objects, purposes and characteristic features of this invention will be in part obvious from the accompanying drawings and will in part Ibe pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be v made to the accompanying drawings in which like reference characters indicate corresponding parts in the several views, and in which:

FIG. 1 illustrates in block diagram form one embodiment of this invention; and

FIGS. 2A and 2B when placed with FIG. 2B to the right of FIG. 2A illustrate diagrammatically one possible embodiment of elements utilizing optical coupling.

Referring now to FIG.. 1, conventional go, stop and trac change signals indicated respectively as G, R and Y are shown for each of the two directions of travel at an intersection. More specifically, the traffic signal for one direction of traffic is designated N-S for a north-south direction, while the other traiiic signal is designated E-W for the east-west direction of traic movement. The north-south direction may be referred to as phase A, while the east-west direction may be referred to as phase B herein.

In the present invention, it is contemplated that the intersection at which the traflic signals are employed may be any one of a plurality of intersections 'wherein it is desirable to have a signal cycle which is variable as well as having variable portions thereof. More specilically, the trac signals may be employed at an intersection where the duration of the go time period is similar for both phase A and phase B. Alternatively, the traic signals may be used at an intersection wherein, for eX- ample, phase A has a relatively long go time period as contrasted to the go time period of phase B or vice versa. Irrespective of the different time periods desired for the traiic signals of phase A and phase B, the apparatus comprising the present invention may be readily adjusted electronically to fulll the desired operating conditions of such traflic signals. l

The traflic signals for both phase A and phase B are controlled during a trafc cycle period according to outputs obtained from a ring counter circuit 12. More specifically, ring counter circuit 12 includes steps numbers 1, 2, 3 and 4 designated respectively 14, 15, 16 and 17. The steps 14-17 are operated in sequence to each provide when operated an output which is employed for operating given traiic signals for phase A and phasel B. In the present embodiment, it is suggested that the output from step 14 be effective to operate the go or green traiic for phase A, while the output from step 15 is effective to operate the traic change signal also for phase A, both outputs from steps 14 and 15 in sequence being operative to control the stop or red signal for phase B. Similarly, the output from step 16 is suggested to be effective to operate the go or green traffic signal of phase B, while the output -frorn step 17 is effective to operate the trac change signal of phase B, both outputs from steps 16 and 17 in sequence functioning to operate the stop or red trac signal of phase A.

Each of these steps 14-17 of ring counter circuit 12 has included therewith a transfer-in circuit referred to as a lamp gate and a transfer-out circuit shown as an AND gate. The lamp gates for steps 14-17 are respectively designated 19, 20, 21 and 22, while the AND gates for such steps are respectively designated 24, 25, 26 and 27. Each of the lamp gates 19-22 has a single input supplied thereto which is coupled from the AND gate included with the preceding step. For example, lamp gate 19 included with step 14 receives an input from AND gate 27 included |with step 17.` Each of the lamp gates 19-22 upon receiving an input provides an output to its corresponding step for transferring operation from the preceding step into its corresponding step.

Each of the AND gates 24-27 includes two inputs, one such input being coupled from its corresponding step while the second input to each of the AND gates 24-27 is coupled from timing circuits 30 over an ADVANCE BUS. Upon receiving such two inputs concurrently, the corresponding AND gate is effective to provide an output to the lamp gate for the succeeding step for transferring operation from its step to such succeeding step.

Ring counter circuit 12 remains in each of its steps 14-17 for a time interval determined by the setting of a variable resistor corresponding to the respective step at the termination of which timing circuit 30 is operated to provide an output on the ADVANCE BUS which is coupled to each of the AND gates 24-27 including the AND gate with the then operating step. Variable resistors 32, 33, 34 and 35 corresponding respectively to steps 14-17 of ring counter circuit 12. Each such variable resistor 32-35 is settable to a position for measuring a time interval in which the corresponding step of ring counter circuit 12 is operative.

Each time timing circuit 36 is controlled to provide an output on the ADVANCE BUS a pulsing circuit 38 is also controlled for a limited time interval during which it provides a pulsed output for rendering a hold circuit 40 inactive. Normally, hold circuit 40 is active and provides an output on a HOLD BUS which is coupled simultaneously to each of the steps 14-17 in ring counter circuit 12 for holding the then energized step in an energized condition during the measured time interval for that step. In the inactive condition of hold circuit 40, a different output is coupled to the steps 14-17 of ring counter circuit 12 for transferring operation from the then energized step to a succeeding step. v

Y Pulsing circuit 38 also provides another output which is coupled to a start circuit 42 for rendering such start circuit inactive for at least a portion of the predetermined time interval during which pulsing circuit 38 is operated in response to its output from timing circuit 3i). Normally, start circuit 42 provides an output to pulsing circuit 38 and timing circuit 30 to insure that such circuits 30 and 38 are effectively operated at the end of a measured time interval for any one of the steps 14-17.

The output from each of the steps 14-17 during its operation is coupled to a matrix selection circuit 44. Such output is selectively coupled by matrix selection 44 to signal control circuits 45 and 46 for phase A and phase B respectively. The signal control circuits 45 and 46 are respectively connected to the trac signals N-S and E-W for controlling the signal lamps of such trafc signals according to the step on which ring counter circiut 12 operates. In this connection, full-wave rectied A.C. energy is coupled to the lamps and in particular to lamp G of signal E-W through a fuse 48.

Each of the signal control circuits 45 and 46 may include a plurality of silicon controlled rectifier circuits, While matrix selection 45 may include a plurality of diode connections such as shown, for example, in pending application Ser. No. 283,105, tiled on May 24, 1963 of which I am co-inventor. Detailed circuitry is disclosed in such pending application Ser. No. 283,105 for selectively operating the lamps R, Y and G for each of phase A and phase B as suggested above for the different portions of the trac cycle. As an alternative, matrix selection 44 may include a plurality of lamp-photoconductor combinations, for example, where a lamp is coupled to each stage of ring counter circuit 12. Such lamp is then energized during the operation of its corresponding stage to irradiate associated photoconductor elements to complete circuits to the traic signals N-S and E-W for energizing the distinctive group of lamps allotted to that stage of ring counter circuit 12.

Push button 50 is employed for the purpose of manually starting ring counter circuit 12 into operation in its step 14. Upon release of push button 50 after ring counter circuit 12 is started into operation, operation of ring counter circuit 12 continues cyclically according to the measurement of the different time intervals.

Referring now to FIGS. 2A and 2B, it is noted that detailed circuits including neon tubes and photoconductor elements are illustrated for ring counter circuit 12, timing circuit 30, pulsing circuit 38, hold circuit 40 and startA circuit 42. In addition, resistors and capacitors are employed with such elements and properly positioned to provide biasing circuits.

A neon tube found suitable in practice is of the type referred to as a miniature neon glow discharge lamp and designated NE2 which is manufactured by the General Electric Company located in Syracuse, New York. A photoconductor element suitable for use in the present invention is of the type designated LBR-O4 manufactured by the Ferroxcube Corporation of America located at Saugerties, New York.

Referring particularly to FIG. 2B, ring counter circuit 12 includes a neon tube for each of its steps 14-17, these neon tubes being designated respectively 52, 53, 54 and 55. Each of the steps 14-17 includes ve photoconductor elements. Such photoconductor elements are designated 60-64 for step 14, 66-70 for step 15, 71-75 for step 16 and 76-80- for step 17. Each of these steps 14-17 includes a second neon tube, these being designated respectively 82, 83, 84 and 85.

The variable resistors 3235 are coupled to photoconductor elements 60, 66, 71 and 76 respectively of steps 14-17 over buses a, b, c and d. It is only when the resistance of each of such photoconductor elements is reduced to a minimum value that (-1-) energy is coupled to the corresponding variable resistor. energy is coupled to photoconductor elements 61, 67, 72 and 77 each of which is further coupled to matrix selection 44 and to signal control circuits 45 and 46. It is only when the resistance of each of such photoconductor elements is reduced to a minimum value that the energy is .actually electrically connected to signal control circuits 45 and 46 through matrix selection 44.

The lamp gate circuits 19-22 corresponding respectively to steps 1417 each includes a neon tube, such neon tubes being designated 82-85 respectively. Each of AND gates 24-27 includes a photoconductor element, a resistor and a capacitor. AND gate 24 includes photoconductor element 64, resistor 87 and capacitor 88. AND gate 25 includes photoconductor element 70, resistor 90 and capacitor 91. AND gate 26 includes photoconductor element 75, resistor 93 and capacitor 94. AND gate 27 includes photoconductor element 80, resistor 96 Iand capacitor 97. y

Photoconductor elements 63, 69, 74 and 79 are provided for the purpose of insuring that capacitors 8S, 91, 94 and 97 are completely discharged. For example, photoconductor element 63 upon receiving light energy from neon tube 52 connects capacitor 91 to energy for completely discharging such capacitor 91.

Optical isolation members 98 are appropriately positioned between the steps 14-17 for optically isolating each step from all of the others. Also, optical isolating members 99 are appropriately positioned (one per step) to optically isolate the neon tube included in the transfer-in circuit from all but one photoconductor element.

Timing circuit 30 includes a neon tube 100 and three photoconductor elements designated 102, 103 and 104. A timing capacitor 105 is coupled to each of the variable resistors 32-35 through a resistance 106.

Pulsing circuit 38 includes three successive stages each including a neon tube and two photoconductor elements. A irst stage includes neon tube 108 and photoconductor elements 109 and 110. A second stage includes neon tube 112 and photoconductor elements 113 and 114. A third state includes neon tube 117 and photoconductor elements 118 and 119. Each of the tirst and second stages includes an RC circuit for insuring turn on of respective neon tubes 108 and 112. The RC circuit for the first stage includes resistor 121 and capacitor 122, while the RC circuit for the second stage includes resistor 124 and capacitor 125. The first stage is optically isolated from the second stage by optical insulating member 127, while the second stage is further optically isolated from the third stage by optical insulating member 128.

Hold circuit 40 includes a neon tube 132 and a photoconductor element 133. A biasing circuit including resistors 134 and 135 and capacitor 136 is provided for governing operation of neon tube 132. Hold circuit 40 is coupled between photoconductor element 133 and resistor 137 over hold bus to each of the steps 14-17 of ring counter circuit 12 for the purpose of holding the last step operated in an operating condition While the time interval is being measured by timing circuit 30 and the corresponding Variable resistor.

Start circuit 42 includes a neon tube 139 and a photoconductor element 140. The purpose of start circuit 42 is to insure that neon tube 100 of timing circuit 32 is properly operated to a conducting condition for a sucient period such that Ipulsing circuit 38 is operated to control hold circuit 40 and start circuit 42 during the time that an `advance `output is provided b y timing circuit 30 over ADVANCE BUS to ring counter circuit 12.

In each of the circuits shown in FIGS. 2A and 2B in w'hich one or more neon `tubes is illustrated, a dotted line arrow is drawn from each such neon tube and directed to lsuch photoconductor elements. Such dotted .line arrows are employed herein to indicate vthat upon conductionof the neon tube, the light energy produced by its glowing is directed to the light receiving portion of the photoconductor element such that the photoconductor element has its resistance reduced to a minimum value for the duration that the light energy is received by the photoconductor element. While each neon tube is nonconductive, it produces no light energy which permits the associated photoconductor elements to be in their high resistance conditions for disconnecting their respective electrical circuits. This operation will become more apparent as the description progresses.

Operation Upon application of energy to the circuits `of FIGS. 2A and 2B, the neon tubes 132 and 139 of hold circuit 40 and startcircuit 42 respectively are immediately operated to conductive conditions. That is, upon'application of energy to hold :circuit 40, capacit-or 136 is charged through resistors 134 and 135 to a level sutiicient to re neon tube 132. Neon tube 132 then conducts causing light energy to be radiated toward photoconductor element 133 -in the direction of arrow 145 for reducing its resistance to a minimum value. energy is coupled through resistor 137 to the HOLD BUS and to each of the steps 14-17 in ring counter circuit 12 in that photoconductor element 109 in pulsing circuit 38 is -in its high resistance condition. (-1-) energy is coupled through resistor 142 to one terminal of neon tube 139 in start circuit 42 causing neon tube 139 to conduct and provide light energy which is directed to photoconductor element 140 in a direction of arrow 147 causing it 'to be in its low resistance condition. energy is coulpled through photoconductor element 140 to timing circuit 30 as well as to pulsing circuit 38, but photoconductor elements 102, 103 and 110` respectively disconnect such energy from their respective circuits normally.

All other neon tubes in the several circuits shown in FIGS. 2A and 2B normally are in their nonconductive conditions. However, neon tube 52 included with step 14 may be manually initiated into conduction by push button 50 so as to initiate `operation of the traffic signal controller.. More specircally, upon actuation of button 50, energy is coupled to Ione terminal of neon tube 52 causing it to conduct. Neon tube 52 during conduction directs light energy to photoconductor elements 60464 in the direction of arrows as illustrated causing each of such photoconductor elements to be in their low resistance conditions. v

Button 50 is only momentarily actuated so as to initiate neon tube 52 into conduction for a suicient duration such that the photoconductor 62 has its resistance reduced to a low value. energy is then coupled through resistor 137 in hold circuit 40 and over the HOLD BUS through photoconductor 62 to the terminal of neon tube 52 'for holding it in conduction. Button 50 is then released and is no longer required for automatic operation of the traffic signal controller. v

A time interval is measured during which neon tube 52 remains conductive as determined by the setting of variable resistor 32. More specifically, upon conduction of neon tube 52, the resistance of photoconductor element 60 is reduced to a low resistance value which causes a timing circuit including variable resistor 32 to be completed. This timing circuit includes photoconductor element 60, bus cz, variable resistor 32, resistor 106 and capacitor 105. Capacitor 105 is charged to the firing level lof neon tube in the time interval predetermined for step 14 by the setting of variable resistor 32 at the vtermination of which neon tube 100 is caused to conduct.

During such measured time interval, (-1-) energy is coupled to signal control circuits 45 and 46 through photoconductor element 61 in its low resistance condition and matrix selection 44 to cause, for example, the go signal for phase A and red or stop signal 'for phase B to be displayed.

Upon conduction of neon tube 100 in timing circuit 30, each of the photoconductor elements 102-104. is irradiated with light energy causing their resistors to be reduced to .la low resistance value. Neon tube 100 is continued in its conduction by the circuit including'photoconductor element` 40 in start circuit 42, resistor 150 and photoconductor element 102 in timing circuit 30. energy is coupled through photoconductor 4element 104 in its low resistance condition over the ADVANCE BUS to charge. capacitor 88 included with step 14 of ring counter circuit 12 in that photoconductor element 64 is in However,

its low resistance condition. Capacitor SS upon being charged to the firing level of neon tube S3 included with step causes neon tube 83 to conduct for a sufficient duration to irradiate photoconductor element 68 for reducing its resistance to a low resistance value for a duration at least until (-1) energy is received over the HOLD BUS for energizing neon tube 53 in step 15.

Neon tube 108 of pulsing circuit 33 in its rst stage is operated to a conductive condition in that capacitor 122 is charged through the circuit including photoconductor element 140 in start circuit 42, photoconductor element 103 in timing circuit 30 and resistor 121. Upon conduction of neon tube 108, it irradiates photoconductor elements 109 and 110 included in stage one of pulsing circuit 38 for reducing their respective resistances to a low resistance value. A circuit is then completed for coupling energy to the HOLD BUS which includes photoconductor elements 133 and 109 in hold circuit 40 and pulsing circuit 38 respectively. With energy on the HOLD BUS, neon tube 52 in step 14 of ring counter circuit 12 is operated to a nonconductive condition which causes each of the photoconductor elements 60-64 to return to their high resistance conditions. The circuit for controlling the traic signals for phase A and phase B including photoconductor element 61 is disconnected to cause the go or proceed indication for phase A and red or stop indication for phase B `to be interrupted. However, step 15 operates to complete a circuit through photoconductor element 67 for operating, for example, the yellow or change signal for phase A and red or stop signal for phase B.

Neon tube 112 in stage 2 of pulsing circuit 38 is operated to a conductive condition in that capacitor 125 is charged to the circuit including photoconductor element 140 in start circuit 42, photoconductor element 110 in stage one of pulsing circuit 38 and resistor 124 in stage two. Upon conduction, neon tube 112 irradiates photoconductor elements 113 and 114 to cause reduction of their resistance to a low resistance value. Photoconductor 113 in its low resistance condition couples energy to the terminal of neon tube 132 and capacitor 136 to cause neon tube 132 to operate to its non-conductive condition. In such nonconductive condition, photoconductor element 133 is no longer irradiated which causes it to returnto its high resistance condition. energy is then disconnected from the HOLD BUS so as to permit the (-1-) energy through vresistor 137 to be coupled to the HOLD BUS and to each of the steps 14-17 in ring counter circuit 12.

In step 15 of ring counter circuit 12, neon tube 53 is operated to a conductive condition in that (-1) energy now appearing on the HOLD BUS is coupled through photoconductor element 68 and to neon tube 53. Neon tube 53 upon conduction irradiates its associated photoconductor elements 66-70 to cause each such photoconductor element to reduce its resistance to a low resistance value.

Neon tube 117 in the third stage of pulsing circuit 33 is operated to a conductive condition as soon as the resistance of photoconductor element 114 is reduced to a minimum resistance value in that (1-) energy is coupled to neon tube 117 through photoconductor element 114 and resistor 154. Upon conduction of neon tube 117, it irradiates photoconductor elements 118 and 119 in the third stage of pulsing circuit 38 causing the resistance thereof to be reduced to a low resistance value. energy is coupled through photoconductor element 118 to the common connection of capacitor 105 and neon tube. 100 in timing circuit 30 to completely discharge capacitor 105 as Well as to cause neon tube 100 to operate to a nonconductive condition. energy is coupled through photoconductor element 119 to neon tube 139 in start circuit 42 causing it to operate to a nonconducting condition. The circuits for operating neon tubes 108 and 112 are interrupted in that photoconductor element 140 returns to its high resistance condition. Upon return of neon tube 112 to its nonconductive condition, photoconductor 113 returns to its high resistance condition for removing the energy from neon tube 132 permitting it to again become conductive.

Neon tube 117 in the third stage of pulsing circuit 38 is operated to its nonconductive condition in response to the return of photoconductor element 114 in its high resistance condition. Photoconductor elements 118 and 119 upon return of neon tube 117 to its nonconductive condition return to their high resistance conditions. Photoconductor element 118 in its high resistance condition permits capacitor 105 to be charged through variable resistor 33 through the circuit including photoconductor element 66 of step 15 and over Wire b. Upon return on photoconductor 119 to its high resistance condition, neon tube 139 in start circuit 42 is again operated to a conductive condition in which it irradiates photoconductor element 140.

Ring counter circuit 12 operates in its step 15 for a time interval measured as determined by the setting of variable resistor 33 during which the yellow or clearance signal for phase A and red or stop signal for phase B are controlled as described above. At the termination of the measured time interval, neon ube in timing circuit 30 is caused to conduct again irradiating photoconductors 102-104 for initiating a pulsing action such as described above. In this connection, the operation of timing circuit 30, pulsing circuit 38, hold circuit 40 and start circuit 42 is similar to that described above.

Upon application of (-1-) energy to the ADVANCE BUS, capacitor 91 included with step 15 of ring counter circuit 12 is charged through photoconductor element 70 in its low resistance condition in resistor 90. Upon reaching the tiring level of neon tube 84 included with step 16, neon tube S4 is caused to conduct. Neon tube 84 upon conduction irradiates photoconductor element 73 included with step 16 causing its resistance to be reduced to a low resistance value. energy is coupled to the HOLD BUS for causing neon tube 53 in step 15 to return to its nonconductive condition prior to the application of (-1-) energy to the HOLD BUS in the manner described above. Such (-1-) energy is coupled through photoconductor element 73 in its low resistance condition for operating neon tube 54 to its conductive condition.

In the conductive condition of neon tube 54, it irradiates the photoconductor elements 71-75 for causing each to assume its low resistance condition. A time interval is measured starting as soon as photoconductor element 71 assumes its low resistance condition in that (-1) energy is coupled through photoconductor element 71 and over Wire c through variable resistor'34 to timing capacitor 105. During such measured time interval, the traflc signals for phase A and phase B are controlled in that (-1-) energy is coupled to signal control circuits 45 and 46 through photoconductor element 72 and matrix selection 44. In step 16, it is suggested that the go or proceed indication for phase B be displayed While the red or'stop indication for phase A be displayed.

Upon termination of the measured time interval for step 16 of ring counter circuit 12, neon tube 100 in timing circuit 30 is again operated to its conductive condition causing photoconductor elements 102-104 to again assume their loW resistance conditions. Timing circuit 30, pulsing circuit 38, hold circuit 40 and start circuit 42 again operate to provide a pulsing output to advance ring counter circuit 12 from its step 16 to its step 17 wherein another time interval is measured during which a different combination `of signal indications are provided. Upon application of (-1-) energy to the ADVANCE BUS, capacitor 94 in step 16 of ring counter circuit 12 is charged through the circuit including resistor 93 and photoconductor element 75 in its low resistance condition. Upon reaching the firing level of neon tube 85, neon tube S5 is operated to a conductive condition. Upon conduction of shown without in any manner departing from the neon tube 85, it irradiates photoconductor element 78 causing it t-o assume its low resistance condition.

Transfer of operation between steps 16 and 17 of ring counter circuit 12 is effected upon operation in sequence of neon tubes S, 112 and 117 of pulsing circuit 38 and neon tube 132 in hold circuit 40 as described above. More particularly, upon conduction of neon tube 108 as described, energy is coupled through photoconductor elements 109 and 133 to the HOLD BUS and to neon tube 54 through photoconductor element 73 in step 16 causing neon tube 54 to operate to its nonconductive condition. Upon' operation of neon tube 112 to its conductive condition, neon tube 132 in hold circuit 40 again is operated to its nonconductive condition for interrupting the energy on the HOLD BUS, but permits (-1-) energy to be coupled to the HOLD BUS. through resistor 137 to hold circuit 40. With energy on the HOLD BUS, neon tube 55 is operated to its conductive condition in that photoconductor element 78 is now in its low resistance condition. Upon conduction of neon tube 55, it irradiates photoconductor elements 76-'80 causing each to assume its low resistance condition for the duration that such neon tube 55 is conductive.

A time interval is measured for step 17 of ring counter circuit 12 which is set by variable resistor 35 and is initiated upon completion of the circuit including photoconductor element 76. As soon as photoconductor element 76 assumes its low resistance condition, energy is coupled therethrough and over wire d through variable resistor 35 and resistor 106 to capacitor 105. Capacitor 105 is charged by such energy to the firing level of neon tube 100 in timing'circuit 30 for advancing ring counter circuit 12 of its step 17 to step 14.

While ring counter circuit 12 `operates in its step 17, the traic signals for phase A and phase B are controlled to display a different combination of traic indications, for example, a red `or stop indication for phase A and a yellow or clearance indication for phase B. In this connection, (-l-) energy is coupled to signal control circuit 45 and 46 through photoconductor element 77 in step 17 and matrix selection 44.

Upon termination of the time interval measured for step 17, neon tube 100 in timing circuit 30 is caused to conduct for again initiating a pulsing action which advances ring counter circuit 12 from its step 17 to its step 14. More specifically, (-1-) energy is coupled to the ADVANCE BUS through photoconductor element 104 in its low resistance condition for charging capacitor 97 through resistor 96 and photoconductor element 80 for charging capacitor 97 to the ring level of neon tube 82 included with step 14 of ring counter circuit 12. Upon conduction of neon tube 82, it irradiates photoconductor element 62 causing it to assume'its low resistance condition.

Pulsing circuit 38 and holding circuit 40 again operate as described above to cause neon tube 52 in step 14 to operate to its conductive condition in which it irradiates lits associated photoconductor elements 60-64 causing each to assume its low resistance condition. The ring counter circuit 12 then recycles through its steps 14-17 in the manner described above for continuously repeatingthe traffic cycle in the time period set by the combination of variable resistors 32-35.

Having described the traiiic signal controller as a specific embodiment of the present invention, it should.

be understood that the embodiment illustrated is considered as being merely typical and that various modifications and alterations may be made to the specic form spirit or scope of this invention.

What I claim is: 1. A controller for governing operation of a traffic signal through the different portions of its cycle compristime for each of said plurality of different conditions in which said cycling means is operative, hold means normally effective to control the operation of said cycling means in the existing condition of its plurality of conditions in which it is operated, transfer means responsive jointly Vto said timing means upon measurement of a predetermined time and -to the condition in which said cycling means is operated for selecting the next inactive con-dition of said cycling means for operation, pulsing means responsive momentarily to said timing means upon measurement of a predetermined time for controlling said transfer means to a condition in which its control of said cycling means is removed, said cycling means being controlled by said hold means upon return to its effective condition to operate in its inactive condition last selected by said transfer means, and control means governed by said cycling means in each of its different conditions for controlling the traflic signal to provide a particular group of signal indications.

2. The controller according to claim 1 in which said cycling means includes a plurality of light generating means, one light generating means allotted to each of said plurality of different conditions when activated for governing said control means, gating means including a plurality of gating elements eachfor at times coupling a dilferent one of said plurality of light generating means i toV said means for activation, each of said plurality of gating elements upon receiving light energy being effective to couple its associated light generating means to `said means, whereby said light generating means is activated to emit light energy, and isolation means positioned for optically coupling the emitted light energy from each of said light generating means onto its associated gating element only.

3. The controller according to claim 2 wherein each of said light generating means is a neon -tube and each of said gating elements is a photoconductor element having a normally high resistance which is reducible to allow resistance upon receiving light energy,'sa.id means being 4. The controller according to claim 2 in which said l timing means includes a plurality of timing elements, one timing element allotted to each of said plurality of different conditions, circuit means for each lof said plurality of conditions including a light receiving element operable only in response to received light energy to select for operation the timing element corresponding to the condition of said plurality of conditions with which it is associated, other circuits means for eaoh of said plurality of diiferent conditions including a light receiving element for each of said plurality of different conditions responsive during reception of light energy for governing said control means, said isolation means being effective to optically couple light energy from the light generating means for each of said plurality of diiferent conditions to only the light receiving elements associated with that condition.

5. The controller according to claim 4 in which'said timing means includes a single voltage storing element which is employed with the selected timing element to store` at least a predetermined voltage for activating said timing means upon measurement of apredetermined time, each of said timing elements being settable to a plurality of different timing conditions each of which measures a different predetermined time required to attain said predetermined Voltage stored by said single voltage storing element, whereby the predetermined time period for each 'of said plurality of conditions of said cyling means is a light emitting means for each condition of said plurality of different conditions of said cycling means, said voltage storing element and said light emitting means for each condition being electrically coupled, optical isolation means for optically isolating each light emitting means from the condition with which the corresponding voltage storage element is associated, circuit means including a light receiving element for each condition of said plurality of different conditions for coupling the output of said timing means to the voltage storage element corresponding to the condition of said cycling means then operating, whereby a voltage stored on such storage element is effective to energize the light emitting means associated with that voltage storage element causing it to emit light energy, and other circuit means having a light receiving element for each condition of said plurality of different conditions including the condition having an activated light generating means responsive to the light energy emitted from the activated light generating means for energizing the light emitting'means for the successive condition during the effective condition of said means.

8. The controller according to claim 7 wherein each of said light emitting elements is a neon tube which is energized upon application of a predetermined voltage to its terminals, each said voltage storing element being a capacitor each for storing the output of said timing means when its associated light generating means for the corresponding condition is activated, said output being similar to said predetermined voltage for energizing the corresponding neon tube.

9. The controller according to claim 2 and further including manual selection means for activating the light generating means for at least one of said plurality of different conditions, whereby said timing means is selectively set to measure the predetermined time for that condition of said cycling means.

16. A controller for governing operation of a traic signal through the different portions of its cycle comprising, in combination, cycling means operable recurrently through its plurality of different conditions in succession, timing means selectively set to measure a predetermined time for each of said plurality of: different conditions in `which said cycling means is operative, means nonmally effective to control the operation of said cycling means in the existing condition of its plurality of conditions in which it is operating, transfer means responsive jointly to said timing means upon measurement of a predetermined time and to the condition in which said cycling means is operating for selecting an inactive condition of said cycling means for operation, pulsing means having a first step responsive to said timing means upon measurement of a predetermined time and a second step responsive to said first step upon its oper-ation, said pulsing means being effective to provide an output in each of said first step and said second step, said means being responsive to the output of said first step and controlled to a condition in which its control of said cycling means is removed, said means further `being responsive to the output of said second step for controlling said means to a condition in which its control of said cycling means is restored, said cycling means being controlled by said means upon restoration to its effective condition to operate its inactive condition last selected by said transfer means, and control means governed by said cycling means in each of its different conditions for controlling said traf-lic signal to provide a particular group of signal indications.

11. The controller according to claim 10 in which said pulsing ymeans includes a third step responsive to its second 12. The controller according to claim -1 1 wherein each of said first step, said second step and said third step includes a light emitting element and at least one light receiving element said light emitting element in said first Step being activated by said timing means upon measurement of a predetermined time for optically governing control of its associated light receiving element, circuit means including the light receiving element of said first step upon being controlled for activating the light emitting element of said second step for optically governing control of the light receiving element associated with said second step, other circuit means including the light receiving element of said second step upon being controlled for activating the light emitting element of said third step for optically governing control of the light receiving element of said third step, said-start circuit means being effective until the -light receiving' element of said third step is activated for holding the light emitting elements of said first step and said second step activated.

13. The controller according to claim 12 wherein said start circuit means includes a light emitting element and circuit means for normally maintaining said light emitting element activated, said circuit means being rendered ineffective in response to activation of the light receiving element of said third step, said start circuit means further including a light receiving element optically coupled to the light emitting element of said start circuit means for activating said light receiving element during the activated condition of said light emitting element, whereby said start circuit means is effective during the activated condition of its light receiving element to hold the light emitting elements of said `rst step and said second step activated after being initially activated.

14. The controller according to claim 13 wherein said light emitting element in said start circuit means is a neon tube and said circuit rneans includes a biasing circuit for coupling a voltage to the terminals of said neon tube for activating such neon tube until the light receiving element of said third step is activated causing such voltage to be shunted around said neon tube, said light receiving element of said start circuit means being a photoconductor element effective during activation of said neon tube to couple energy to said'first step and said second step during the activated condition of said neon tube.

1S. The controller according to claim 12 in which each of said first step and said second step includes a light 'receiving element, circuit means including the light receiving element of said `first step for rendering said means ineffective to control the operation of said cycling means and other circuit means including the light receiving element of said second step when activated to res-tore said means to its effective condition in which it controls the operation of said cycling means.

16. The controllr according to claim 15 in which said means includes a control circuit having a light emitting element which is normally activated and a biasing circuit which is effective to couple control energy to said cycling means for controlling its operation, said biasing circuit including a light receiving element in said first step of said pulsing means and a light receiving element in said means responsive to light energy received from the light emitting element therein for removing said control energy upon activation of said first step, said control circuit of said means being electrically coupled to the light receiving element of said second step of said pulsing means, whereby activation of said second step interrupts control of the light emitting element of said means causing the light emitting element of said means to be deactivated and the biasing circuit to be interrupted for coupling said control energy to said cycling means for its operation.

No references cited.

NEIL Cf READ, Primary Examiner. 

1. A CONTROLLER FOR GOVERNING OPERATION OF A TRAFFIC SIGNAL THROUGH THE DIFFERENT PORTIONS OF ITS CYCLE COMPRISING, IN COMBINATION, CYCLING MEANS OPERABLE RECURRENTLY THROUGH ITS PLURLITY OF DIFFERENT CONDITIONS IN SUCCESSION, TIMING MEANS SELECTIVELY SET TO MEASURE A PREDETERMINED TIME FOR EACH OF SAID PLURALITY OF DIFFERENT CONDITIONS IN WHICH SAID CYCLING MEANS IS OPERATIVE, HOLD MEANS NORMALLY EFFECTIVE TO CONTROL THE OPERATION OF SAID CYCLING MEANS IN THE EXISTING CONDITION OF ITS PLURALITY OF CONDITIONS IN WHICH IT IS OPERATED, TRANSFER MEANS RESPONSIVE JOINTLY TO SAID TIMING MEANS UPON MEASUREMENT OF A PREDETERMINED TIME AND TO THE CONDITION IN WHICH SAID CYCLING MEANS IS OPERATED FOR SELECTING THE NEXT INACTIVE CONDITION OF SAID CYCLING MEANS FOR OPERATION, PULSING MEANS RESPONSIVE MOMENTARILY TO SAID TIMING MEANS UPON MEASUREMENT OF A PREDETERMINED TIME FOR CONTROLLING 